Thanks to everyone who took the time to review my story :)
AN: Chapter betaed by Miette and dstone12

Severus sat at his desk, the classroom door closed as he waited for the clock to finally reach eight o'clock to welcome his first class.
He had dressed carefully, with dark blue pants and shirt under a black Mao cut knee length robe. The fabrics were sturdy and monochrome but with a hint of elegance. His hair was braided carefully in the traditional way most Wizards still observed in public when they had not cut their hair short Muggleborn-style. Minerva had not commented on his appearance when she had shown him to the classroom but he had spied a glint of approval in her eyes.
Dhaal was continuing his beauty rest under Severus' desk after grumbling all the way at being woken up so early. Severus had not reminded his Familiar that he was the one who refused to let Severus come to Hogwarts on his own.

When, one evening, Severus had asked Lucius and Narcissa if they had ideas of what he should practice to keep his students in line during the classes, Lucius had laughed and told him that "if he could handle Werewolves, students did not have a chance". Narcissa had smacked her husband playfully then told Severus that he would be just fine if he used the same voice trick that worked so well on Nymphea and Draco when they were obviously looking for trouble to get into. Severus had no idea what she meant, but had concluded that he only needed to be himself. If he was overwhelmed, he could always send Dhaal to charm them.

He rose smoothly as the bell finally chimed and opened his door. The corridor was suspiciously silent, all seven students patiently waiting at the door and watching him in silent interest. Severus looked at them for a few seconds, letting his eyes roam over them to imprint their face and Sense in his mind before gesturing for the students to enter.

"Please do not sit next to someone from your House."

Three Gryffindors, one Ravenclaw, one Hufflepuffs and two Slytherins.
At least, he noticed no obvious animosity between them as the students settled down hesitantly. He had arranged eight tables into a half circle to encourage discussion and better observe his charges. He himself would sit in front of them behind a smaller desk than the one usually used by teachers for quicker access to individual students once practical work began.
Severus had put on the desk his notes for the class with tentative lesson plans as well as the list of his students and their photographs. While they settled down, he quickly identified each of them.

Alixan. Slytherin. Muggleborn.
Cromby. Gryffindor. Pureblood.
Wakefield. Ravenclaw. Pureblood.
Lewis. Gryffindor. Muggleborn.
Anderson. Hufflepuff. Muggleborn. He had not even noticed her House in December, but he would have pegged her more as a Gryffindor.
Parkes. Gryffindor. Muggleborn.
Thickey. Slytherin. Muggleborn.

They were the group identified as having some difficulty in practicals because their grasp of the theory made them overly cautious, much like Severus had been in his first year.

"Before we begin, I'd like to introduce myself," stated Severus as he faced them, slightly leaning on his desk. "My name is Severus Caspian. I am currently studying Transfiguration under Professor McGonagall, and teaching you is part of my homework."

As he had hoped, his last words earned him a few smiles.

"You may call me Apprentice Caspian while at school. If we ever meet outside Hogwarts, I will be Lord or Master Caspian."

He was not surprised to see incomprehension on the Gryffindors' and Hufflepuff's face.

"If you do not understand why I am making this distinction, I strongly advise you to look up wizarding etiquettes. Wizarding traditions may not be amiss either. Now, I studied at Hogwarts until the end of my fifth year when I passed both my OWLs and my NEWTs."

He ignored the students' surprised gasps and went on, hoping his speech did not feel as rehearsed as it was.
"I then took on an Apprenticeship for four years, at the end of which I was awarded the ranks of Potion and Runes Master grade I, Defence against the Dark Arts and Herbology Master grade II. The Lupacem potion was part of my end-of-Apprenticeship project. It allows Transitional Werewolves to transform painlessly and keep their mind during the three days of the full moon. Coupled with a special wand I created in collaboration with Wandmaker Maverick, it allows them the same level of control over themselves as Full Werewolves possess."

"Do you have any questions?" asked Severus, knowing they needed to get them out of their system if he wanted them focused on the lesson later.

"What are Full and Transitional Werewolves?" asked Wakefield.

Severus was surprised by the question as he had thought the students had had a presentation on Werewolves when Hogwarts had officially allowed werewolf students inside her walls. He would need to speak with McGonagall on the subject as the students needed to know more on Werewolves when they lived beside some. It was also true for other creatures like Vampires, Faes and even Giants as discussions were engaged to allow them to study at Hogwarts, the werewolf students having set a precedent.

"Full Werewolves are Werewolves who are not controlled by their wolf. They can remain in human form during the full moon if they so choose. Transitional Werewolves are the ones we are most familiar with, who have not yet learned how to control their wolf," answered Severus.

"What was your House?" asked Alixan.

Severus did not doubt the slytherin student knew the answer. What point was she hoping to make to the others though, Severus was not sure. Did she want everyone to know the gryffindor McGonagall had taken a Slytherin under her wing?

"Slytherin," answered Severus. "Do not expect any favouritism from me, I only value hard work," he added pointedly.

"Of course not, Sir," answered the Slytherin respectfully.

"If you do not have other questions..." trailed off Severus.

All the students shook their heads. Thank Merlin they were first years.

"Let's begin then. What do you know of Transfiguration and its mechanisms?" asked Severus.

He expected the students to stall, look at their shoes or each other until either one finally had the courage to speak or he had to design a volunteer. Instead, Anderson spoke up immediately. Was it because of their brief interaction before Christmas? No matter the cause, he was grateful.

"Transfiguration is the use of Magic to change an object or a living specimen into something else. Living specimens include plants, animals, and magical beings."

"Very good, five points to Hufflepuff," said Severus. "How is it different from Charms?"

"Charms add or subtract properties from objects or creatures while Transfiguration affects the object or creature itself," answered Anderson immediately. "Most spells fall under either Charms or Transfiguration definition."

Severus was impressed. It was not the word for word definitions from the textbooks, meaning she understood what she was saying.

"Exactly. Five more points to Hufflepuff. What else can anyone tell me about Transfiguration?" asked Severus, letting his gaze wander on the other students.

To his surprise, a Gryffindor raised his hand.

"Mister Parkes?"

"Transfiguration is divided into four branches, Transformation, Untransfiguration, Vanishment, and Conjuration."

"Indeed, can you elaborate?" asked Severus.

"Transformation is the art of altering an object or a living specimen. Untransfiguration is the art of cancelling a transformation. Vanishment is the breaking of an object into Magic, making it seem as if the object has disappeared. Conjuration is the transformation of one of the four elemental Magics into its element primary state."

Severus nodded.

"Five points to Gryffindor. Can someone give me a bit more detail on Conjuration? Mister Thickey?" asked Severus as he saw the Slytherin boy hesitate.

"The four material elements are present in the air...or rather space... around us in the form of Magic itself. Conjuration allows us to change them from Magic to their primary state. We can conjure water in liquid form, fire as a flame, earth as soil and air as wind. The four elements cannot be transformed. For example, you cannot transform water into ice even though ice is another state of water."

"Very good, five points to Slytherin," said Severus. "To obtain ice from water, you can use a cooling charm for example. It will lower the temperature of water until it becomes ice. Remember that to be effective, your best bet is to combine several kinds of Magic to obtain the best result, be it Transfiguration and Charms, or Potions and Runes. Anything else on Transfiguration?"

"Transfiguration is governed by Gamp's Law of Elemental Transfiguration with its five principal exceptions," answered Wakefield. "The first exception is that you cannot create food out of thin air, and more generally that you cannot transform air into something tangible with the exception of the four elements' primary state as we already discussed. The second is that you cannot transform inanimate into animate. For example, you can transform a porcupine into a pin cushion but the reverse is not true. The third law-"

"Very Good Miss Wakefield," interrupted Severus. "Five points to Ravenclaw. Now I would like your comrades to get the chance to earn points too, I am certain you know the three other exceptions so can anyone else give me one of the remaining Gamp's law exceptions?"

"I have a question Sir," said Parkes respectfully.

"Go on," nodded Severus, hoping he would have the answer.

"The second exception says you cannot transform inanimate into animate but my older brother transformed a teapot into a spider once to try to scare me."

Idiot brother, thought Severus but he kept his face impassive.

"Did the spider remain a spider?" asked Severus.

"No sir. It turned back into a teapot maybe one minute later," answered Parkes.

Cromby frowned.
"Then it was not a Transformation. Professor McGonagall told us any transfiguration was fixed until you untransfigured them."

Severus nodded.
"Five points to Gryffindor. As we said before, you can transform a porcupine into a pin cushion, though that is cruel and there are laws against unnecessary cruelty to animals, but you cannot transform a pin cushion into a porcupine. Some have tried and died trying. Why? Because it required more Magic than they possessed to make it work. Imagine, you would require enough Magic to first transfigure the pin cushion into a porcupine with all of his organs and bones, and then you would need to give him life. As you must know, no one can resuscitate the dead. By the same token, no one can transform inanimate into animate."

Severus paused, letting his words sink in, pleased to see that all the students were taking notes.
"What Mister Parkes' brother did was transform the teapot into something which looked and moved like a spider but was not one. He gave movement and texture to an illusion, if you want. It must have been tiring, which is the reason why it reverted to a teapot after a short time. It was not a Transformation," explained Severus firmly. "Now, who can tell me the third exception? Miss Lewis?"

The Gryffindor girl answered obediently.
"As a consequence of the previous exception, you cannot transfigure inanimate matter into nourishment. It's true for foods like meat and dairy which come from animals, for vegetables like peas and carrots but also foods like flour or sugar because they still originally come from living plants."

Severus nodded in approval.
"Five points to Gryffindor. I really want to emphasise this point. You may have seen someone duplicate food, bread for example. They did not create even one tiny bit of bread from thin air. Instead, they took a part from the initial bread then enlarged it and gave it the right form to obtain the second bread. I know it's not intuitive," added Severus with a slight upturn of the lips. "Are we all clear on this?"

He was pleasantly surprised by the answering chorus of "yes Sir" coming from the seven students. This teaching thing might not be unbearable after all, with motivated students.

Moving on, he nodded to Anderson who had raised her hand.

"The fourth exception states that the distance between the caster and the subject or object to be transfigured must be less than about 2 meters."

"Indeed," agreed Severus. "Can you tell me why? I know it's not in your books, but do you have a theory?"

The girl took the time to think before answering. Severus was pleased to notice that the other students seemed to do so as well.

"Well, I suppose the farther you are, the less your Magic will be able to reach the object you want to transform," finally answered Anderson, biting her lips in uncertainty.

Severus nodded. She was close enough. Without Sensing, spells were not guaranteed to follow the Magic flows leading to objects, thus losing intensity the farther they had to go.
"Yes, your spells will lose intensity because of the distance, and because your Magic may be absorbed by other objects it encounters on its way to your target. Remember, the greater the distance, the higher the possibility of interferences between your spell and its target. Be careful, it can actually lead to core exhaustion if your intent is strong and you keep on feeding the spell when you are too far away to correctly affect your target. Five points to Hufflepuff."

Thickey frowned.
"But sir, it's true for all spells."

"True," answered Severus, pleased to see his students think. "You must take this into account every time you use Magic. However, it's even more important for Transfiguration because it affects the core of the object the spell is cast on, which already usually requires more magic intensity than other spells. Five points to Slytherin. Now, the last exception to Gamp's law?"

"No transfiguration can succeed if its Boltzmann number is greater than 1000," answered Cromby.

"Five points to Gryffindor," nodded Severus. "Can anyone explain what this means?"

After several minutes of silence, Severus turned to the Ravenclaw. He should not have been surprised, it was the most complicated of the five exceptions and most students did not give it more than a passing thought until fourth year.

"Miss Wakefield?"

The girl nodded vigorously before launching into her explanation.
"The quantity of Magic contained in one's core is called the Boltzmann number. Wizards do not all possess the same quantity of Magic in their core. A Muggle's Boltzmann number is equal to zero. 1000 corresponds to Merlin's Boltzmann core and has never been equalled by any other Wizard to date. Boltzmann numbers are difficult to estimate as they can vary over time."

"Thank you, five points to Ravenclaw," said Severus once he was certain she had nothing more to add.

"I know this is not exactly in the first year curriculum but I think it's important for your grasp of Transfiguration to understand this," explained Severus. "As Miss Wakefield explained, and I hope you all noted everything she said, Boltzmann numbers are difficult to estimate. They are determined through spell castings. There is a consensus that Wizards able to cast wandless spells possess a Boltzmann number at or above 750. Wizards who attend Hogwarts possess a Boltzmann number at or above 250. Wizards able to cast the Patronus spell or to become Animagi possess a Boltzmann number over 500, though you can possess a Boltzmann better than 500 and still fail to cast the Patronus spell. There is a list of charms, spells and curses which can be used to evaluate your Boltzmann number, you can find them in the more advanced Transfiguration books or ask Professor McGonagall about them. Boltzmann numbers are very important because they tell you if you're risking too much, even death, when you cast a transfiguration spell. Contrary to charms spells that will simply fail if your Boltzmann number is too low, Transfiguration spells will exhaust your core if they require more Magic than you can provide, more often than not leading to coma then death."

Severus repressed a smile as every student wrote his words on their parchment.

"Now, when do we use those Boltzmann numbers? Miss Alixan?"

"We compare them with the result of our transfiguration spell equation before attempting to cast the spell," answered the Slytherin.

"Indeed. Does one spell possess a unique equation?" asked Severus.

"No," answered Alixan. "It depends on the path you've chosen to achieve your Transfiguration."

"Five points to Slytherin," said Severus.

"But no matter the path we use, as long as the Transfiguration works, why does it matter?" asked Lewis perplexed.

"I won't answer you right away," said Severus. "Why don't you and Mister Cromby come to the blackboard? You will both write me the equation of the spell to transform a matchstick into a needle. However, Mister Cromby will first transform his matchstick into the form of the needle then into steel while you will first transform your matchstick into steel before giving it the form of a needle."

The two students got up to the board without protest. They spent more time than Severus would have liked to write and resolve the equations but their results were correct.

"Very well. What can we say when we compare the results of those two transformations equations?" asked Severus to Cromby.

"I will use less Magic if I first give my matchstick the form of a needle then transform it into steel than the contrary," answered the Gryffindor boy.

"But both numbers are under 250, under our Boltzmann numbers, so in both cases, we do not risk a core exhaustion," piped in Lewis.

"True in this case. But if you needed to cast another spell immediately afterwards, wouldn't you rather have used up the least amount of Magic?" replied Severus patiently. "Moreover, if you were not powerful enough to come to Hogwarts, you might be able to perform this transformation if you used the path requiring the least amount of Magic."

"And for another transformation, it might be important if one path is under our Boltzmann number, and another is above it?" asked Wakefield.

"Exactly," nodded Severus. "You must remember two things. First, the more different the result of your transformation is from the beginning, the more quantity of magic it will require. Two, the path you use is also very important. In our example, the matchstick and the needle have almost the same size and form but their materials are very different. It would be even harder to transform wood into gold because both wood and steel are partly made of carbon which is not the case for gold. In our example, it's easier to first give the right form then convert wood into steel than the reverse because steel requires more Magic to model than wood. However, in another case, you maybe should first change the material then the form and size. You must use the equations to choose the best order of operation before making the various transformations."

"But Sir, do we really only use our core Magic to cast spells?" asked Thickey.

Clearly, this one had heard of inside and outside Magic.

"First years usually do. At the very least, they do not know when they are using outside Magic or their own Magic. As long as you are not able to tell, you cannot cast spells which would require more Magic than your core possesses."

He paused, taking the time to gaze at each student, before continuing.
"Our class exercises until fifth year included are, of course, designed to be below 250 Boltzmann units no matter the path you chose. Until then, even if you make a mistake with your equation, you will not risk hurting yourself with one of the class' exercises. This is only a concern if you get ahead of yourself by designing your own transfigurations before you know enough. Don't hesitate to ask if you have any concerns. Neither Professor McGonagall nor myself will fault you for wanting to be sure you will not hurt yourself."

All students were still taking notes frantically.
Looking up at the clock, Severus was surprised to see he only had two minutes before the end of the lesson.

"Alright everyone. This is all for today. I want you to really think about what we talked of today so that if you have more questions, you can ask them to Professor McGonagall next week. We will see each other again in two weeks, when we will begin to work on your weaknesses so please, think about what you think you need to work on in order to improve."

Professor McGonagall and he had already discussed exercises for each group but he wanted to see if the students would reach the same conclusion as them.

The students got up when the bell rang, cheerfully bidding him goodbye.

He was exhausted. Only three more classes to go.

Two and a half hours later found Severus groaning as he put his head on his crossed arms. His second class had been far less knowledgeable on Transfiguration theory than his first. He had expected it, but the depth of their ignorance had been surprising, especially when he remembered their practicals in December which had been far from bad. They truly managed to cast spells without understanding the theory behind them. It was dangerous and at least, he thought he had managed to make them understand the need for caution when using Transfiguration.

He looked up at the clock. Only forty-five minutes before his next class. He had avoided the great hall and gone to the kitchen instead to get his lunch directly from the House-Elves. They had been surprisingly deferential in addition to their usual helpfulness. He wondered if it was because he now was part of the staff or because of Tuei.
Of course, after checking that Hogwarts did not prevent him from Sensing Severus, Dhaal had elected to remain in the kitchen with the hope of cajoling more sweets out of the House Elves.

"Good day, Protector."

Severus almost jumped in surprise. He had not Sensed the Ghost arrive.

"Good day to you, Baron," answered Severus.

"If you have time to spare, I believe I have an answer to your previous enquiry."

"I have time," answered Severus immediately.

"Follow me then."

Walking beside a Ghost was a novel experience for Severus. At first, he was unbalanced as he had gotten used to Sensing the persons and creatures around him. Walking next to what appeared to be empty to his Sense while seeing the Ghost was disturbing and he kept trying to Sense the Baron over.
Several stairs and turns later, Severus felt more at ease, though he was perplexed when the Baron stopped in front of a wall on the castle's seventh floor.

"You need to focus on what you need and walk past this spot three times," said the Baron.

If the Ghost had been anyone else, Severus would have thought he was playing a prank.

Focusing on the Horcrux's diffuse Sense and his need to find it, Severus walked past the blank wall three times. A door appeared right on the previously blank spot.

"I don't think Hogwarts will ever cease to amaze me," stated Severus as his Sense zoomed in on the Horcrux which suddenly clearly was behind that door.

He hesitated a brief instant before Sense-calling for Dhaal. He could not let his excitation overcome his cautiousness, and he had promised Augustus not to approach the Horcrux on his own.

His Familiar did not take long to join him, and immediately went to perch on Severus' shoulder.

"I'm ready," Sensed his Familiar while lightly rubbing his head against Severus' ear.

"Thank you," Sensed back Severus warmly, before focusing on the task at hand.

He carefully checked for nasty surprises but did not Sense any harmful protections in the room. He supposed there were limits to what Lord Voldemort could achieve within Hogwarts. To have hidden one Horcrux in this particular room already was an impressive defence.

Nodding to himself, he opened the door and walked into the room, Dhaal still on his shoulder and the Baron behind him.

The room could only be called a storeroom. It was full of various objects haphazardly piled up, from books to armour as well as clothes and trinkets. The Horcrux was in the left corner of the room. A diadem put on a dummy.
Severus cast his Patronus, the form of the Nundu, Kea, immediately taking guard in front of him, and carefully extended his Sense around the diadem. He felt Dhaal tense up as the Horcrux tried to catch Severus' Magic but Severus' shield prevented it from grasping it. It tried to whisper into Severus' mind but Kea was not allowing it. Severus almost thought he heard his Patronus growl, but it had to be a trick of his mind.
After several minutes, Severus was certain the Horcrux was not protected by anything else than its own power. He would have been able to take the Horcrux right now if he had brought the right tools. Why had he not taken a box with him? Yes, he had not expected to find the Horcrux today. Yes, they had not tested the boxes yet. But he should have been prepared. A Slytherin always ought to be.

Sighing to himself, Severus went out of the room. The door disappeared as soon as it was shut.

"Those things are really disgusting."

"Thank you for your wonderful input, Dhaal," answered Severus dryly.

"Seriously, how did he not Sense the wrongness after making so many of them? Isn't he supposed to be almost as clever as you?" Sensed Dhaal, irritation flowing from him.

Severus refrained a sigh.
"I already told you how lucky I was to be apprenticed to Drunek. Even Augustus does not know as much as I do about Sensing and Khorlos.

"But Augustus is not as curious about Magic as you are, contrary to your Marvolo. Why—"

"You found what you were looking for."

Severus did not show his relief at the Ghost' interruption of Dhaal's coming rant. While his Familiar now understood and grudgingly supported Severus' plan to help Lord Voldemort, it did not prevent him from criticizing the Lord's past poor decisions.

"Yes. Thank you, Baron. I do not have the right tools for now, but as soon as I do, I will take this away from Hogwarts."

"And destroy it."

"It may not be necessary," countered Severus.

"An abomination such as this one cannot be allowed to remain," hissed the Baron. "How can you call yourself Protector when you would allow it to exist!"

"This is not what I said Baron," replied Severus firmly, looking at the Ghost right in the eyes. "I will deal with this abomination as you call it."

The Baron looked at him for a long time, as if trying to read through his soul.

"Very well, Protector. I will trust you to handle this matter as you think best."

"Thank you for your trust Baron. I won't disappoint you," swore Severus. "This room is a true wonder. I don't understand, even as well hidden as it was, why I could not locate the problem more precisely."

"According to the House-Elf who helped me, Protector, this room is one of Hogwarts' few which are located on another magical place unless someone requires their use. You walking three time in front of the wall while focusing on your need created a bridge between the room's natural plane and ours, aligning both planes and allowing you to access the room for a time."

"Are you saying I wouldn't be able to remain inside the room for an infinite time?" asked Severus, intrigued at the possibilities the Baron was revealing.

"Indeed. Two different magic planes cannot always be aligned or you risk creating an imbalance and I have no idea how it would affect both planes. I'm afraid I am not an expert in such matters as it is a peculiar branch of Magic but I have no doubt that if it interests you, you will find ways to assuage your curiosity," answered the Ghost.

It was a dismissal if Severus had ever heard one.

"Thank you once more for your help Baron. I promise you I won't disappoint you," said Severus earnestly. "Now I must go back to my class before I'm late."

"I did my duty, Protector. Remember to do yours," replied the Ghost before disappearing without a sound.

Severus slowly walked back to his class, holding back a groan as he spotted the curious and eager faces of his students waiting in front of his door. Dhaal hastily Sensed Severus that he was going to spend the afternoon with Hagrid and Fang, and jumped away from his shoulder before he could be asked to suffer through the afternoon classes for moral support.
Severus really wished he could meet with his co-conspirators right now to share his discoveries instead of teaching Transfiguration for four more hours. How teachers did not die of boredom teaching the same things over and again was a mystery.

Oh joy, Finnegan was part of this group. He did not wish to deal with arrogant Gryffindors.

Steeling himself, Severus put on his best impassive face and strode past the students, wandlessly opened his classroom's door and gestured for them to follow him. He did not smirk at the awed whispers that followed his demonstration of wandless Magic. He could do this.

Four hours later, Severus did not linger after his classes. His afternoon students had been more rowdy than his morning ones, and he had needed to project his Magic at the beginning of both classes to nip in the bud the attempts at undermining his authority. His goblin mask as well as a few cutting comebacks had also done wonders to ensure his complete control over the students until the end of the classes.
He promised Minerva they would debrief his first classes on Friday and the older Professor did not insist on him reporting immediately. Her amused look as he left her office told Severus she was well aware of his level of exhaustion after teaching the whole day, as well as his surprise at this fact.
He begged off Narcissa's offer of an early diner and dropped in his bed instead. He did not wake up before the next morning, when his alarm rang.

Severus spent the morning with Lucius who tutored him on Heads of Houses' boring business while Dhaal elected to spend the day with their Goblin family. Severus felt quite envious of his Familiar's plans for the day, but he could not shirk his duty. After lunch, he went to his room with the goal of examining his future possibilities. Life would not stop after the elections no matter the outcome and he could not afford to be caught unprepared for any eventuality.
The Lupacem potion was already assuring him a steady income and Hoardrock had predicted it would last for the next several years. Severus had also been asked to speak at several conferences and universities all over the world for an astounding amount of galleons. He was comfortable enough not to need to worry about finding a steady job for several years, but he needed to decide the best way to occupy his days.
Until the Horcruxes matter was resolved, Severus could not take on more than his Apprenticeship with Professor McGonagall. Afterwards, he would still need Lucius' tutoring on Heads of Houses' responsibilities though the time required would likely decrease. It left him with enough time for conferences and to work on his project for family Ressurs. Once this project was done, he could begin thinking about his project for Land Utpatti. He could work on adapting Wizard potions for Vampires and other magical beings at the same time.
Thinking back to his talk with Hoardrock, he was even more convinced that he wanted to own his own Apothecary. But he did not want a classic apothecary, only brewing common potions every day. Even if he decided to hire potionners to do the latter, his main interest was still improving existing potions and creating new ones. Even better when he got to mix potions with another field of Magic like runes. So, should he establish himself as an independent researcher, and look into what spurred his interest or take on requests from others? Should he look into a partnership with Saint Mungo's to work on health-improving treatments? The latter would require him to study the Healing Arts, which would be interesting once he was done with his Transfiguration apprenticeship.
He also needed to begin to work on his interest in exploring muggle research methods and biochemistry in relation to Potions.

He smiled wryly to himself as Lucius' admonishment from this morning resonated in his head. His brother wanted him to do more than focus on his magical interests. He wanted Severus to build a true House, meaning to look into new members to swear into Caspian House.
Severus felt his mood darken. His brother often teased him on how much Severus was researching when he had just finished his Apprenticeship and earned four Masteries. Each time, it reminded Severus of everything going on his brother had not been privy to. Of everything at stake. He could not help but feel that all his future plans would be for naught if they failed to heal Lord Voldemort's core. And if they succeeded but Birkins won…

Severus stood up with a sigh. He would not get anything done today. He went to the living room, hoping to spend time with Narcissa and Draco, a sure way to lift his mood. To his surprise, Narcissa was wearing her Healer's attire.

"Severus! I was going to come up to warn you I'll be at Saint Mungo's for the afternoon," said Narcissa with a smile.

"Back to your practical study?" asked Severus.

"Yes, Healer Abbot finally deemed me recovered enough. Would you believe how frustrating it is to study spells without being able to cast them?"

He smiled at her fondly.
"I can imagine."

Narcissa's difficult pregnancy, her son's early birth and her subsequent long recovery had put her Healer's internship on hold. She had spent the last year studying with books only and Severus understood she had to be itching to test all she had learnt.
She still had four years before taking her HOPEs, the Healing Operating and Pharmacopeia Exams, but while some nasty gossips pretended she would not last that long, Severus knew better.

Narcissa studied him intently before speaking again.
"Do you want to come with me? I'm sure you could learn a thing or two."

Severus blinked at the unexpected proposal. He had no wish to become a Healer. However, it could be useful in many ways to study how Healers used Sensing on their patients.
"I would love to, but are you sure I won't intrude?"

He could almost see her roll her eyes though she only tilted her head on the side.

"We have various observers every day. I wouldn't have asked if I wasn't sure you could be present. Plus, you are the Lupacem inventor. It will open a few doors for you for some time. You may not be able to escape once the Healer-Researchers get their hands on you though."

Severus stared at her as he processed her words. He had received a letter from Saint Mungo's requesting that he hold a conference on the Lupacem and its creation, but nothing to suggest as much interest in him as Narcissa was implying. It had been one letter among many others from private researchers, smaller British Hospitals as well as foreign ones.

"Right. Give me five minutes to change into more practical robes."

Severus was true to his words, and five minutes later, they were walking towards the edge of the Malfoy domain. Narcissa had opted not to have Saint Mungo's floo linked to the manor. They were going to apparate in front of Saint Mungo's visitors' entrance as Severus had to get an observer's authorization.

"Why didn't you choose to link the manor's floo to Saint Mungo's?" asked Severus, curious. "The floo is well protected and there are wards to separate it from the main house."

Narcissa smiled.
"I did not want the hospital to call for me at any hours just to test my resolve as Lady Malfoy. Most did not expect me to last six months. A few thought I would give up once Draco was born. I will get the floo linked to the hospital I will be attached to once I'm a full Healer."

She had alluded to those difficulties previously.

"Do you regret having chosen to be a student instead of an Apprentice?" asked Severus, knowing how much he owed to Drunek for his guidance.

"No, as a student, I get the chance to study under several Healers with various techniques, though even Apprentices must study under different Healers other than their Master during their last two years. I think I would have enjoyed being an Apprentice if I had just gotten out of Hogwarts, but I was already married to Lucius and planning to bear his children when I began my studies. From what you told us, your Master becomes part of your family. It was not practical. Of course, I mostly judge from what you told us of your Apprenticeship and you've been quite closed-mouth on the subject, especially your Master," answered Narcissa as she looked at him pointedly.

"I told you about my Master in my letters and when I've come back," protested Severus, though he was well aware of everything he was not telling his family. Yet.

Narcissa stopped to face him.
"Really? Let's see, your Master is married, has three children, one who was born during your Apprenticeship. His own Master taught you for a while. You've really grown attached to him and his family, and… That's all. We don't know his first name or those of his family, and you always come up with an excuse for not having them over for tea. You won't even show us their pictures."

She sounded hurt, despite her face being as smooth as ever. Severus had thought he had managed evading his family's questions about his Apprenticeship better.

"Nothing would make me happier than having all of you together with me for a day. As you said, they are a part of my family now, as Lucius, Draco and yourself are," answered Severus slowly, carefully choosing his words while trying to show her he meant his words. " However, my Master has no wish to get involved in our cause. He doesn't care which side wins. I have never hidden that I would actively support Lord Voldemort's campaign once I became a Master. He respects my choice but he doesn't want to be seen as taking a side."

Narcissa seemed to relax a bit.
"He has a family to care for. And you're afraid some would see them as your weaknesses as they are not under our Lord's protection. I understand. We'll meet them once the new Minister has been elected then."

Severus gave her a small smile.
"As soon as it's safe to."

"You remind me of my sister sometimes," said Narcissa unexpectedly.

He hoped she was speaking of Andromeda.

She laughed, as if reading his mind.
"I'm speaking of Andromeda, of course. She is as protective of her family as you are. Bellatrix cares much more for herself, though that was not always the case."

Severus had no idea how to navigate the traitorous sea of the Black family.

"She did not seem to hate Draco," he finally offered.

"You really think so?" asked Narcissa, a hint of vulnerability creeping through her voice.

He supposed sisterly Bonds were stronger than madness. To be honest, Bellatrix had seemed to try not to scare Draco the one and only time she had held him in her arms. Her wrongness had been quieter than usual during those few seconds, though it had only reared back in force the moment Draco had gone back in his Mother's arms.

"I do."

He did not mention that Dhaal was invisible and on high alert every time Bellatrix visited the Manor, hovering near Draco and ready to strike at any hint of a suspicious move by Narcissa's sister.

"When we were younger, Andromeda was the one who made sure we got along. She called us the Black Sisters, as if we were a music band," said Narcissa, smiling fondly.

Andromeda eloping with Ted would have been even more of a betrayal.

As if reading his thoughts, Narcissa added:
"Once, I wondered if Bellatrix had helped Andromeda escape to her Muggle. I thought Andromeda would never have been able to confound the Bond with Uncle Orion long enough to marry Ted otherwise. But Bella was so angry afterwards…"

"Did you ask Andromeda?" asked Severus. He had trouble imagining Bellatrix helping her sister for love.

Narcissa shook her head.
"Despite our reconciliation, some subjects remain too painful to address today. In a few years, I hope…"

"It's the same with Augustus," said Severus, feeling that she deserved something in return for her trust.

They shared a smile of understanding, then Narcissa took Severus' arm, leading him once more along the path. They walked in silence for a few minutes.

When Severus spoke again, he was focused on Saint Mungo's.
"What should I know about Healing that you won't have the time to explain during the visit?"

Narcissa took her time before answering.
"Well, most observers are other Healers, Healer-Researchers, Healer students or Apprentices so they all possess a basic understanding of healing. I assume you know about personal and impersonal Magic?"

"Do you mean inside and outside Magic?"

"Yes. Impersonal Magic is the Magic which exists around us. Personal Magic is the Magic which belongs to us and exists inside us. You and I each possess our own personal Magic. It's produced by our core. Our core is very important because it's the beginning of all the magical patterns which exist inside our body, and because it's the place where personal and impersonal magic can meet to cast spells though they must never merge."

Severus nodded, Narcissa's explanation was coherent with his goblin teachings.

"We all possess a unique assortment of magic patterns inside our body, though there is about a ninety-five percent match of patterns between any two Wizards. These patterns are disturbed when we are sick or injured, and it's the Healer's goal to put the patterns back as they should be. Healers study standard patterns but they must also be able to feel the personal Magic of their patient to know if they chose the right pattern, as I told you that each patient is a bit different from the other."

Severus had the feeling Narcissa was oversimplifying greatly the importance of the patterns but he understood the idea behind it.

"It's very important that Healers only use impersonal magic to put their patient's patterns back in order, and even then only a small amount or the patient's internal Magic will turn against their help. They can also use the patient's own Magic but must be careful not to... seize it too tightly for fear of disrupting the patient's body's global pattern."

Severus was relieved that it did not contradict his Sensing knowledge.

Narcissa was observing him with a wry smile. He raised an eyebrow askance.

"I know you have four Masteries, that you created the Lupacem, that you created your own House, but I still did not expect you to just absorb my explanations like this."

Severus shrugged.
"What you told me confirms some of what I learnt during my Apprenticeship."

"Of course."

She did not say more and they walked the short remaining distance to the end of the domain in silent contemplation. From there, Narcissa apparated them in front of St Mungo's Hospital for Magical Maladies and Injuries.

Despite the Lupacem, Severus had never been to Magical Britain's foremost hospital. Its front was different from Gringotts' or the Ministry's, yet it seemed just as many people were coming and going out of it.
He followed Narcissa as she led him through the front door to the welcoming desk on the right. All the other persons present were queuing at the desk on the left.

"Good morning Mrs Allison," said Narcissa to the woman behind the desk.

"Good morning student Malfoy," answered the woman with a smile. "Welcome back to Saint Mungo's."

"Thank you. Severus will accompany me as an observer today," explained Narcissa as she gestured toward him. "You should have him on the approved list under Lord Caspian."

The woman looked up sharply, eyes rounded in surprise.
"Lord Caspian? You managed to have him come?"

Narcissa and he were definitely going to need to have a talk.

"Yes, but he's here to observe," answered Narcissa firmly. " However, I believe he could be convinced to spare half an hour for the Director and the Researchers if they so wish," added Narcissa as she turned toward Severus.

He tilted his head as if he was thinking hard about the offer before speaking.
"I could meet with them for a short time, let's say around five if they'd like to."

Allison nodded excitedly.
"I'm booking you in their schedule right now. Please go to the director's office at five. Student Malfoy will get someone to show you there. Here is your visitor identification."

Severus was surprised not to be asked for his wand like in the ministry, but understood why only seconds later when he stepped through the doors separating the welcoming hall from the rest of the buildings. He Sensed various protecting wards, and spied two guards posted nearby.
He did not have the time to dwell on those as Narcissa led him to the lift. They went to the third floor where Severus could only stare as Healers and Nurses bustled around with practised efficiency.

From this moment, he was swept off in a whirl of motions as he followed Narcissa and Healer Abbot while they made the tour of the patients' rooms, and then settled in one of the examination rooms where they saw patients to establish diagnosis and give out prescriptions.
All along, Severus focused on Sensing the interactions between the Healer's Magic and the patients'. He had never focused his Sense so long before and it was more tiring than practising the Chen form under Richtigk's eyes. He was almost relieved when the time came to meet with the Director and five Healers-Researchers who were each the Head of one branch of Saint Mungo research department.

However, his relief was short-lived when, after singing his praises for long minutes, the Researchers began questioning the rigour of his research.

"Are you implying that I deliberately conducted the tests on the Lupacem in order to obtain falsely positive results?" asked Severus, barely keeping his outrage in check behind his Occlumency fumes and only managing to keep his voice steady, if a bit cold, by sheer goblin training.

"Of course not, Master Caspian," denied Researcher Calderon, flustered. "Your research and tests were extremely well documented, and your method was flawless for a preliminary study."

"Then why did you have to do so many additional tests to license it?" asked Severus, crossing his arms at the man's contradictory statements.

"What Researcher Calderon means, Lord Caspian," intervened Director Smethwick smoothly, "is that trial standards are different between preliminary study and Potion licence approvals for use by the public. The role of a preliminary study is to find which direction the research should go, and then to perfect the experiment until you find a prototype you deem acceptable with sufficient chances of success. The role of the Licensing tests is to check the potion for efficiency and innocuousness to the population, as well as evaluate the risks it poses versus the improvements it brings. As such, the group of patients tested for a license approval, that we call a cohort, must be representative of the population that will use the potion in the future. This cohort must be large enough to detect any serious secondary effect that could be caused by the potion, as well as comprise testers of various age, weight, Boltzmann numbers, and other influential parameters to be representative of the population the potion will be licensed for."

It was quite rational, almost obvious in the way that important concepts could be once you were aware of their existence, and Severus felt his anger make way for curiosity and interest.

It must have shown because Researcher Calderon spoke up next.
"Another imperative is to check the potion effectivity and exclude any placebo effect. Researchers realised about 200 years ago that giving patients something that looked like a potion could be as effective to cure them as to give them a potion. We observed that patients believing in a cure can sometimes be enough for their Magic to act and heal them. As such, we always perform what we call randomised tests. The population tested is cut in two equivalent halves. One half is given the potion, one half is given the placebo, but the patients don't know what they are getting. If the half getting the potion gets better results than the one given the placebo, then the potion is truly effective."

This was absolutely fascinating. Severus listened with rapt attention as the Healers explained in detail all the other biases that could impact an experiment — some he already knew, others he had never suspected — and the various methods to lessen or cancel those biases. The fact that they were keeping apprised of the evolution of testing methods in the muggle world to check their applicability in the Wizarding World was even more impressive.

Far too soon, Director Smethwick coughed loudly, told them that if Severus agreed to work with Saint Mungo, he would have long days to learn about their methods of research and trial, and then went on to explain exactly what they expected from Severus. The meeting then devolved into chaos, all appearance of method forgotten in the face of the Researchers' eagerness and excitement. Apparently, they wanted him to work with them on every possible cure they could think of. Severus lasted forty-five minutes before finally telling them to draft a Contract and send it to Gringotts for his future examination.

Narcissa had waited for him, and the promise of chocolate macarons for dessert as well as the knowledge that his presence might improve her status in Saint Mungo's gave Severus a boost of energy. They spent the evening relaxing, Lucius teasing Severus as he proposed the most improbable people as future members of Caspian House.